1. Field of the Invention
The present invention relates to a parking assisting apparatus for assisting parking of a vehicle, particularly to a parking assisting apparatus for sampling a rear image by a camera, displaying the rear image on a display in the vehicle and assisting a driver in the parking operation.
2. Description of the Related Art
Conventionally, there has been known a method of assisting a beginner unaccustomed to parking such as parking a vehicle lengthwise side by side in a row or backing a vehicle rearwardly into a parking space in the parking operation. For example, according to Japanese Patent Laid-Open No. 17328/1995, a CCD camera or a distance sensor for measuring a distance is provided on a vehicle body, the area adjacent the vehicle is inspected and an image of the area adjacent the vehicle is displayed on a display monitor provided in the compartment of the vehicle to thereby provide a driver with a view of the surrounding area.
Further, according to Japanese Patent Laid-Open No. 201082/1984, there is known a method in which the steering wheel angle is detected by a steering sensor and a steering wheel operating angle is calculated and outputted by a simplified display. Further, according to Japanese Patent Laid-Open No. 2357/1996, there is also known a method in which a distance between a vehicle and an obstacle (particularly, a vehicle parking contiguous to a parking space to which a driver intends to park the vehicle being driven) is measured by a distance measuring sensor for detecting an object adjacent the rear of the vehicle, a position of starting to turn the steering wheel by a maximum steering angle is detected in accordance with the distance and the wheel turning start position is informed to the driver.
However, according to the above-described conventional methods, an obstacle adjacent a vehicle is detected by using various sensing technologies as a premise and a system for the processing becomes complicated. Further, according to the method of measuring the distance to an obstacle in the vicinity by the distance measuring sensor and informing the driver of the distance, it is difficult to deal with a case in which there is no vehicle parking contiguously to a parking space or a case of abrupt rush by a person and accordingly, the parking operation is not properly assisted.
Hence, in order to resolve such problems, a parking assisting apparatus was proposed with the object of assisting the parking operation by a simplified method and providing a driver with pertinent, useful information in the parking operation in Japanese Patent Laid-Open No. 334470/1999. According to the apparatus, the space adjacent the rear side of a driving vehicle is scanned by a camera installed on the rear side of the vehicle and an image sampled by the camera is displayed on a display in the vehicle as a rear image and in the steering operation, a running prediction locus which is varied depending on a steering wheel angle of the vehicle is displayed to overlap the rear image to thereby assist the driver in the parking operation at a right angle.
However, according to such an apparatus for displaying the running prediction locus to overlap the rear image, when parking a vehicle rearwardly, there is achieved an advantage of being capable of providing the driver with useful information of the surroundings, when the apparatus is actually used, particularly in parking along a longitudinal line, the steering wheel needs to turn back in the midst of operation. It is difficult to determine the timing of how much the steering wheel is to be turned and thereafter turned back. The timing is difficult for a beginner driver having a short driving history and skill to some degree is needed.
Hence, the invention has been carried out in view of the above-described problems and it is the technical problem of the invention to provide a parking assisting apparatus capable of carrying out the operation of parking relaxedly even by a beginner and pertinently assisting the driver in a parking operation.
In order to resolve the above-described problems, according to an aspect of the invention, there is provided a parking assisting apparatus for taking an image of the area adjacent the rear side of a vehicle by a camera (17) in a parking operation, displaying an image from the camera on a display (13) provided inside the vehicle as a rear image and displaying a running prediction locus (20) varied in accordance with the state of a steering wheel angle to overlap the rear image, said parking assisting apparatus (1) comprising:
parking instructing means (4b) for instructing a driver how to park the vehicle along a longitudinal line and running prediction locus displaying means (9, 11, 12, 13) for displaying the running prediction locus (20a) having a point of inflection in accordance with the steering wheel angle when the vehicle is being parked along the longitudinal line by the parking instructing means.
Accordingly, when the vehicle is being parked along the longitudinal line by the parking instructing means, the running prediction locus having the point of inflection is displayed in accordance with the steering wheel angle and accordingly, in the case of parking the vehicle along the longitudinal line, the driver can know, while staying at an initial position, whether the vehicle can be parked along the horizontal line at a parking space on the rear side based on the running prediction locus having the point of inflection (for example, substantially constituting an S-like shape). In this case, a steering amount necessary for parking the vehicle along the longitudinal line can be known at an initial stage of the parking operation and therefore even a beginner can relaxedly park the vehicle.
According to the running prediction locus, when the longitudinal line parking of the vehicle is displayed within a predetermined range (L in FIG. 15) by which the vehicle can be parked along the longitudinal line in accordance with characteristics of the vehicle and a marker (20b) is displayed at a vicinity of a rear side face of the running prediction locus (20a), operation and determination by a display portion of the displayed marker can pertinently be carried out based on the marker.
When there are further provided regressing state detecting means (3, 5, 6) for detecting a regressing state of the vehicle and inflection point determining means (11) for determining a point of inflection (PT) in parking the vehicle along the longitudinal line by he characteristics of the vehicle when the vehicle starts regressing and before the vehicle reaches the point of inflection, the running prediction locus is switched to and displayed by the running prediction locus (20) at and after the point of inflection in accordance with the steering wheel angle, the regressing state can be detected and an operational state up to the point of inflection can be known in compliance with an actual rear image by the position of the marker. That is, timing of how much a steering wheel is to be turned and thereafter turned back becomes easy to determine on a screen where the rear side is displayed by the marker.
Further, in the case in which the position of the marker becomes parallel with a road side or a curb stone (40) or when an end portion (20c) of the running prediction locus becomes parallel with a vehicle parked rearwardly the vehicle being parked along the longitudinal line, the vehicle is regarded to reach the point of inflection and display of the running prediction locus is switched. After the vehicle passes through the point of inflection, the running prediction locus is displayed in accordance with the steering wheel angle in conformity with a rear side vehicle in parking or the steering wheel angle is displayed on a straight line to indicate a neutral state or the display screen is distinguished to thereby change the display mode and an operational state can be made easy to understand for the driver.